Patent EA-003909-B1 (EA)
Title: Cerium based abrasive material, raw material thereof and method for their preparation
Inventor: YAMASAKI HIDEHIKO
IPC: C01F17/235
Filed: 2001-04-06
Abstract: 1. A stock material for cerium-based abrasives, used as a stock material for production of cerium-based abrasives, containing a carbonate and an oxide of cerium-based rare earth, and having a loss on ignition of 0.5 to 25% on a dry basis, determined by heating at 1000 degree C for 1 hour. 2. The stock material for cerium-based abrasives according to claim 1, wherein said loss on ignition is 5.0 to 20%. 3. The stock material for cerium-based abrasives according to claim 1, wherein said loss on ignition is 1.0 to 5.0%. 4. A method of producing a stock material for cerium-based abrasives comprising, as main ingredients, a mixture of carbonate and an oxide of cerium-based rare earth, wherein said carbonate and oxide of cerium-based rare earth are mixed with each other in a ratio to give a loss on ignition of 0.5 to 25% on a dry basis, determined by heating at 1000 degree C for 1 hour. 5. A method of producing a stock material for cerium-based abrasives comprising, as main ingredients, a mixture of a carbonate and an oxide of cerium-based rare earth, wherein said carbonate is partly converted into the oxide by calcination under conditions of temperature and time adjusted in such a way to give the stock material mixture loss on ignition of 0.5 to 25% on a dry basis, determined by heating at 1000 degree C for 1 hour. 6. The method of producing a stock material for cerium-based abrasives according to claim 4 or 5, wherein said loss on ignition is 5.0 to 20%. 7. A method of producing cerium-based abrasives comprising slurrying and/or wet crushing, filtration, drying, and roasting of the stock material for cerium-based abrasives according to one of any claims 1 to 3, or the stock material for cerium-based abrasives produced by the method according to one of any claims 4 to 6. 8. The method of producing cerium-based abrasives according to claim 7, further comprising treatment of the stock material with a mineral acid after the slurrying and/or wet crushing but before the filtration. 9. The method of producing cerium-based abrasives according to claim 7, further comprising fluorination of the stock material after the slurrying and/or wet crushing but before the filtration. 10. The method of producing cerium-based abrasives according to claim 8, further comprising fluorination of the stock material before the filtration. 11. A method of producing a stock material for cerium-based abrasives comprising, as main ingredients, a mixture of a carbonate and an oxide of cerium-based rare earth, wherein said carbonate is calcined at 400 to 850 degree C to be partly converted into the oxide. 12. The method of producing a stock material for cerium-based abrasives according to claim 11, wherein said carbonate is calcined for 0.1 to 48 hours. 13. A stock material for cerium-based abrasives, produced by the method according to claim 11 or 12. 14. A stock material for cerium-based abrasives containing the stock material for cerium-based abrasives according to claim 13 and having a loss on ignition of 1.0 to 20% on a dry basis, determined by heating at 1000 degree C for 1 hour. 15. A method of producing cerium-based abrasives, comprising crushing and fluorinating the stock material for cerium-based abrasives according to claim 13 or 14, and roasting the fluorinated stock material at 700 to 1000 degree C. 16. The method of producing cerium-based abrasives according to one of any claim 9, 10 or 15, wherein said fluorination is effected with the aid of ammonium fluoride and/or hydrofluoric acid. 17. A cerium-based abrasive produced by the method according to one of any claims 7 to 10, or claim 15 or 16.